Flotation process



Patented oct. 29V, 1929 l 1,733,570

UNITED STATES PATENTOFFICE HARRY R. WILSON, F TOOELE, UTAH FLOTATION PROCESS Application filed April 3, 1928. Serial No. 266,910.

In the concentration of certain ores I have grade of concentrate). This middling is refound that economy and an improved yield turned to the head of the first cell.

can be obtained by the use of amyl Xanthate. The tails from the first section, still fairly This Xanthate differs from the Xanthates genrich in lead, go to the first cell of the second erally used in flotation processes in that it section. Here more amyl Xanthate is added 55 is made with amyl alcohol instead of ethyl together with sodium sulphide. A concenalcohol or propyl alcohol. trate is collected and the tails go to the second 1 have made up the amyl Xanthate of ap'- cell of the second section in the same manner proximately the following percentages. as explained above for the first section. |The 1 Per cent tails from the second cell go to the following 60 NaOH 19.6 CellS IOm Which a middling is collected and Am l alcohol 43.2 returned t0 the first cell. The concentrates Carbon bisulphide 372 from the first section are combined with those of the second section to form the final con- Thls agent Soollros lmProYel llotatloll re' centrates. The final tails. nearly depleted of e5 sultsin the treatment of oxidized or partially lead and Silver, go to Wa's OXlllZefl leads Sllyor imo ooPPor oros- The foregoing process has been practiced A SPeolllo example 1 5 tllo treatrrlorlt of tm" on several ores and ore mixtures without the tic ores. These are silicious oxidized leadaddition of a frother 01. other agent in the S-lv'er ores f-rom *the district' in in first Stage. In other ores there have been Wlllcll the SllVor 1S Partly oomblllol Wltll the added in the first stage pine oil as a frother load and Partly 1n the form of argorlto'laro' and sodium silicate to depress, or deaden slt@ (a hyrous Sulphate 0f potasswm and the fiotabiiity of the gangue materials. in lrorl oarrylllg somo SllVol'l- From tllls oro ores where the slime and the.gangue fioat a lllgll roooyory Carl be obtflllloo loy room?! easily, sodium silicate is used in order to get 75 to the PlllP amyl Xalltllato and Soolrum Sul a clean concentrate. The crude amyl xan- Plllolo or amyl Xantllato alone; tlmo 1S; Wltllthate has enough frothing power to give av out the SolPlllle though or oXolllC-lmg other proper froth without the use of pine oil, but agents helelleftel referred' t0. where desired pine oil may be advantageously 3o The eQCOmPmylnL drawlng 1S a f loW Sheet added in small quantities to give more froth, 8o lllustralmg Such aProceso- Tllo oro l5 glOllnd and the silicate to depress certain portions in the usual manner by the use of Crushers, 0i the Ore, rolls, ball mills, etc. The pulp from the ball In the second stage, more amyl Xanthate mill (or rather from-olie classifier that folis added together with the sulphide. The lows the ball .mill) goes to the first cell 0f latter increases the flotability of the lead. It 85 the first SeCtlOIl. Here amyl Xenthate iS is not all added at once, but in successive added, and a concentrate collected. The tails stages; part in the first cell, part in the second, from the first cell go to the second cell, where and s0 on. This is advisable because the more concentrate is Collected. Amyl Xanaddition of the entire requirement of the sul- 40 thate is also added here if necessary. The phide in the first cell tends to kill the froth, 90 tails from the second cell go to the third cell, making the bubbles smaller and glassy, like and the operation is repeated in the fourth Water bubbles, because they carry no meta and following cells. The number of cells used burden@ VThe quantity of sodium sulphide depends on the amount of lead in the ore, and added has a decided effect on the recovery of the ease with which it is floated. The concenlead. The quantity supplied to each cell 95 trates get successively leaner in lead content should be regulated in accordance with the in the successive cells, so that when the comamount of lead contained in the pulp as it inercial limit of grade of concentrate is reaches the cell in question. reached,"the next following cells are used to In the case of one ore, a concentrate was collect a middling (which is really a poor made containing lead, 53.9 per cent; silver 100 cop 15.1 ounces per ton and gold 0.22 ounces per ton. For this ore I have used the following quantities per ton of ore treated, namely, sodium amyl xanthate 1 pound; pine oil 0.2 pounds and sodium sulphide 2 pounds. The recovery was 96.2 per cent of the lead, 90.8 per cent of the silver and 80 per cent of the gold.

On another ore, a concentrate was made containing 45.4 per cent of lead and 22.04 ounces per ton of silver. treated, I have xanthate, pounds of sodium silicate and 0.08 pound of pine oil. l

The reason for making two concentrates or working the process in two stages, as shown on the flow sheet, is because of the manner in which the`silver is carried in the ore; partly with the lead and partly in the form of argento-jarosite.

A high recovery of lead and silver can be obtained with amyl xanthate amyl xanthate together with sodium sulphide. But when the Xanthate is used alone it gives a poorer grade of concentrate and junction with it. But if the sulphide is addand with the in the second ore containing oxidized grade copper-silver of silicates and copper, probably a mixture carbonates.

The process may be used with advantage also in connection with straight oxide lead flotation and with other oxidized ores. With some oxidized copper ores lime has to be added to give an alkaline pulp. In general with the be added at the start.

otation operations are grinding, agitation and Wi th suitable frothing.

Various other proportions of the flotation agents may be used than those specied above. usel oil is a commercial or impure amyl alcohol which is cheaper than and may be used instead of pure amyl alcohol in making up the Xanthate. Potassium hydroxide may be used in place of sodium hydroxide, but the latter is preferable because it is cheaper.

The usual sort of practiced, such as aeration, together alone or withA copper ores sodium sulphide may Y I claim is: 1. In the froth floating. of an oxidized of argento-jarosite, the xantliate alone in a first stage and withdrawing a froth concentrate comparatively high in silver, and the adding of amyl xanthate an a sulphide in a second stage and withdrawing a froth concentrate comparatively high in lead.

2. A method of froth floating lead silver ore of the type described which comprises adding amyl xanthate alone in a first stage, withdrawing a .froth concentrate com concentrates comparatively high in lead.

In witness whereof, I have hereunto signed myname.

HARRY R. WILSON. 

